{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,12]],"date-time":"2026-09-12T05:08:02Z","timestamp":1789189682483,"version":"build-2803163510"},"reference-count":42,"publisher":"MDPI AG","issue":"18","license":[{"start":{"date-parts":[[2026,9,10]],"date-time":"2026-09-10T00:00:00Z","timestamp":1788998400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"crossref","award":["32171885"],"award-info":[{"award-number":["32171885"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"crossref"}]},{"award":["32171885"],"award-info":[{"award-number":["32171885"]}],"id":[{"id":"https:\/\/ror.org\/01h0zpd94","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>Bamboo is a renewable material widely used in traditional Chinese musical instruments, but its vibration behavior is sensitive to moisture. This study investigated how moisture content affects the vibration behavior of Jinghu bamboo soundboxes. Three Xipi and three Erhuang specimens were conditioned by soaking and drying to obtain 11 moisture states (M0\u2013M10). Time domain responses, frequency response functions, natural frequencies, damping ratios, mode shapes, and a frequency-mass-based estimated structural stiffness index were evaluated using impact hammer testing and experimental modal analysis. Three individual Xipi soundboxes with nominal storage durations of 3, 46, and 86 years were examined before and after conditioning at 20 \u00b0C and 60% relative humidity as an exploratory case comparison. Both types showed stronger vibration responses at intermediate moisture levels, whereas nearly dry and nearly saturated conditions produced weaker responses. Increasing moisture generally lowered resonance frequencies and estimated structural stiffness index, while damping ratios were higher at the moisture extremes. Under the present test conditions, Xipi specimens exhibited a higher estimated structural stiffness index and stronger mid- to high-frequency responses than Erhuang specimens. Given the differences in specimen geometry and mass, these variations are interpreted as reflecting whole-structure dynamic responses rather than intrinsic differences in material properties. In the exploratory comparison, XP-86 showed the largest change, with a 61.17% decrease in fundamental frequency and the development of surface cracks. Given the limited number of independent specimens, the results are interpreted descriptively rather than as statistically generalizable effects. These results s demonstrate the importance of humidity control during the use and preservation of Jinghu soundboxes.<\/jats:p>","DOI":"10.3390\/ma19183853","type":"journal-article","created":{"date-parts":[[2026,9,10]],"date-time":"2026-09-10T10:27:21Z","timestamp":1789036041000},"page":"3853","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Effects of Moisture Content on the Acoustic Vibration and Modal Characteristics of Jinghu Soundboxes"],"prefix":"10.3390","volume":"19","author":[{"given":"Yiyang","family":"Ge","sequence":"first","affiliation":[{"name":"Institute of Biomaterials for Bamboo and Rattan Resources, International Centre for Bamboo and Rattan, Beijing 100102, China"},{"name":"Key Laboratory of National Forestry and Grassland Administration, Beijing for Bamboo & Rattan Science and Technology, Beijing 100102, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ying","family":"Li","sequence":"additional","affiliation":[{"name":"Institute of Biomaterials for Bamboo and Rattan Resources, International Centre for Bamboo and Rattan, Beijing 100102, China"},{"name":"Key Laboratory of National Forestry and Grassland Administration, Beijing for Bamboo & Rattan Science and Technology, Beijing 100102, China"},{"name":"School of Materials Science and Technology, Beijing Forestry University, Beijing 100083, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Wen","family":"Fu","sequence":"additional","affiliation":[{"name":"Institute of Biomaterials for Bamboo and Rattan Resources, International Centre for Bamboo and Rattan, Beijing 100102, China"},{"name":"Key Laboratory of National Forestry and Grassland Administration, Beijing for Bamboo & Rattan Science and Technology, Beijing 100102, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0004-9770-4852","authenticated-orcid":false,"given":"Rongzhen","family":"Song","sequence":"additional","affiliation":[{"name":"Institute of Biomaterials for Bamboo and Rattan Resources, International Centre for Bamboo and Rattan, Beijing 100102, China"},{"name":"Key Laboratory of National Forestry and Grassland Administration, Beijing for Bamboo & Rattan Science and Technology, Beijing 100102, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xiang","family":"Zhao","sequence":"additional","affiliation":[{"name":"Institute of Biomaterials for Bamboo and Rattan Resources, International Centre for Bamboo and Rattan, Beijing 100102, China"},{"name":"Key Laboratory of National Forestry and Grassland Administration, Beijing for Bamboo & Rattan Science and Technology, Beijing 100102, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shanyu","family":"Han","sequence":"additional","affiliation":[{"name":"Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Materials Science and Engineering, Nanjing Forestry University, Nanjing 210037, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zehui","family":"Jiang","sequence":"additional","affiliation":[{"name":"Institute of Biomaterials for Bamboo and Rattan Resources, International Centre for Bamboo and Rattan, Beijing 100102, China"},{"name":"Key Laboratory of National Forestry and Grassland Administration, Beijing for Bamboo & Rattan Science and Technology, Beijing 100102, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1200-5234","authenticated-orcid":false,"given":"Fuming","family":"Chen","sequence":"additional","affiliation":[{"name":"Institute of Biomaterials for Bamboo and Rattan Resources, International Centre for Bamboo and Rattan, Beijing 100102, China"},{"name":"Key Laboratory of National Forestry and Grassland Administration, Beijing for Bamboo & Rattan Science and Technology, Beijing 100102, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,9,10]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"115554","DOI":"10.1016\/j.indcrop.2022.115554","article-title":"An environmentally friendly and efficient method to improve the acoustic vibration performance of bamboo for musical instruments: Nitrogen-protected heat treatment","volume":"188","author":"Deng","year":"2022","journal-title":"Ind. 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